1. [mid-19C+] (US) to beat someone up; to crush.
2. [late 19C+] (orig. US theatre) to make oneself attractive to a member of the opposite sex, to flirt with, to succeed in seduction; thus mashing
3. [1940s+] (US black) to give one what is due; thus mash it on me, give it to me; mash me a fin, loan me $5.
4. [1950s] (W.I.) to seduce, to rape.
5. [1970s] (US) to masturbate.
6. [1980s] (US black) to pass over stolen or contraband goods.
7. [1980s+] (US campus) to kiss, to neck.
8. [1980s+] (US black) to work hard, to commit oneself to a task.
9. [1990s+] to fondle the breasts in an aggressive manner.
10. [2000s] (US black) to have sexual intercourse in an aggressive manner.
[1900s] (N.Z.) amorous.
1. [late 19C–1930s] the act of flirting, seducing, making advances; also attrib.
2. [late 19C] used adv., affecting the style of a masher n. (2)
[2000s] (UK black) a thug.
see separate entries.
see knock into a cocked hat under knock into v.
1. [1950s+] (W.I., Rasta/UK black) to achieve a huge success; to do something well.
2. [1990s+] (W.I.) an expression of encouragement.
[1970s+] (US black) to have sexual intercourse.
1. (orig. US/W.I.) to destroy, to break, to beat up, of a relationship, to break up.
2. (W.I.) to get oneself into trouble.
3. (W.I.) to cause trouble.
[1980s+] (US campus) to kiss, to neck.
SE in slang uses
[1940s] (W.I.) to move along, to make room, as in a crowded bus; also to accelerate a car.
[1960s+] (US) to accelerate.